ABSTRACT
To compare the relative heat sensitivities of human normal and neoplastic cells of the same tissue type, a study was carried out of the relative sensitivities to heat of granulocyte/macrophage progenitor cells (CFU-GM) derived from the peripheral blood and bone marrow of normal subjects and patients with chronic granulocytic leukaemia (CGL). Nucleated haemopoietic cells were incubated at temperatures in the range 41.5 degrees C to 44.0 degrees C for various periods before culture in agar. The results of these experiments showed that CFU-GM from normal blood were consistently less sensitive to damage by heat than normal marrow CFU-GM. There was no comparable difference in the relative heat sensitivities of CFU-GM from blood and marrow of patients with CGL and no significant difference between the heat sensitivities of CFU-GM derived from marrow from normal individuals and patients with CGL. The observed difference in heat sensitivity of CFU-GM from normal blood and marrow accords with other data suggesting that the two progenitor cell compartments are distinct: the blood CFU-GM may represent a more primitive population of committed progenitor cells. In CGL, CFU-GM in the blood may much more closely resemble those in the marrow. The data provide no support for the hypothesis that malignant cells differ intrinsically from their normal counterparts in respect of sensitivity to damage by hyperthermia.
Subject(s)
Hematopoietic Stem Cells/physiology , Hot Temperature , Leukemia, Myeloid/physiopathology , Cell Survival , Cells, Cultured , Female , Granulocytes/physiology , Humans , Leukemia, Myeloid/pathology , Macrophages/physiology , MaleABSTRACT
Human marrow fibroblasts were grown in vitro and examined for effects on human and mouse haemopoietic cells. When human marrow cells were incubated with fibroblasts or with fibroblast-conditioned medium for 1 week and then assayed for committed granulocyte/monocyte (CFU-c) and erythroid (BFU-e) progenitor cells, the numbers of CFU-c and BFU-e were considerably increased compared with controls. In contrast, human marrow-fibroblast-conditioned medium, when added directly to CFU-c or BFU-e assay cultures, had no effect on colony formation by these progenitor cells. As these results suggest that the fibroblast-derived factor may be acting on a relatively primitive progenitor cell, possibly a pluripotent haemopoietic stem cell, the effect of this factor on mouse pluirpotent haemopoietic stem cells (CFU-s) was examined. Human marrow-fibroblast-conditioned medium considerably enhanced CFU-s survival after a 24 h incubation and increased the proportion of CFU-s in cell-cycle. The increase in CFU-s survival depended on the concentration of the fibroblast-conditioned medium but not on the age of the fibroblast culture. The evidence suggests therefore that human marrow fibroblasts produce a factor that acts on a human myeloid progenitor cell more primitive than BFU-e and CFU-c, possibly the pluripotent haemopoietic stem cell.
Subject(s)
Bone Marrow/analysis , Hematopoietic Stem Cells/drug effects , Animals , Cell Survival/drug effects , Cells, Cultured , Colony-Forming Units Assay , Erythrocytes/drug effects , Fibroblasts/analysis , Granulocytes/drug effects , Humans , Hydroxyurea/pharmacology , Male , Mice , Monocytes/drug effects , Time FactorsABSTRACT
When mouse bone marrow or spleen cells were incubated for 24 hours in medium conditioned by marrow adherent cells, the survival of pluripotent hemopoietic stem cells (CFUs) was considerably greater than that of stem cells incubated in fresh or spleen-conditioned medium. Medium conditioned by endosteal cells also increased marrow CFUs survival. Survival of CFUs more than 24 hours was greater when fresh marrow was incubated directly with marrow adherent cells than with medium conditioned by these cells. Although marrow-conditioned medium greatly increased CFUs susceptibility to 3H-thymidine suicide, DNA synthesis inhibitors did not prevent the increased survival of CUFs in marrow-conditioned medium. These results indicate that marrow stromal cells produce a factor that increases CFUs survival in vitro independently of proliferation.
Subject(s)
Bone Marrow Cells , Hematopoietic Stem Cells/physiology , Animals , Cell Division/drug effects , Cell Survival/drug effects , Cells, Cultured , Culture Media , DNA/biosynthesis , Hematopoietic Stem Cells/cytology , Hydroxyurea/pharmacology , Male , Mice , Spleen/cytology , Thymidine/pharmacologyABSTRACT
Media conditioned by marrow adherent cells from anaemic Sl/Sld and W/Wv mice increased the 24-h survival of CBA CFUs in vitro compared to fresh medium to about the same extent as marrow-conditioned medium from normal Sl+/Sl+, W+/W+, and CBA mice. Sl/Sld marrow-conditioned medium also increased the percentage of CFUs in DNA synthesis to the same extent as CBA marrow-conditioned medium. These results demonstrate that Sl/Sld mice produce a marrow stromal factor that increases both survival of CFUs and the percentage of CFUs in DNA synthesis in vitro. Therefore, the defective haemopoietic microenvironment of Sl/Sld mice is not due to a deficiency in the production of this factor.
Subject(s)
Bone Marrow Cells , Hematopoietic Stem Cells/cytology , Animals , Bone Marrow/analysis , Cell Survival , Cells, Cultured , Colony-Forming Units Assay , Colony-Stimulating Factors , Culture Media , Hematopoietic Stem Cells/physiology , Mice , Mice, Inbred CBA , Mice, Inbred StrainsABSTRACT
When mouse bone marrow was incubated in medium conditioned by marrow fibroblasts, the survival of pluripotent stem cells (CFUs) was considerably greater than when marrow was incubated in fresh medium. This increase in CFUs survival depended on the age of the marrow fibroblast culture, the initial number of cells in the culture, and the concentration of the conditioned medium. Medium conditioned by fibroblasts from other adult tissues--spleen, bone, and subcutaneous tissue--did not increase CFUs survival, but medium conditioned by embryo bone did. The increase in CFUs survival by marrow-fibroblast-conditioned medium was not accompanied by any change in the total number of nucleated cells of the incubated marrow nor by any comparable increase in the survival of granulopoietic stem cells (CFUc) or erythropoietic stem cells (BFUE). These results indicate that marrow fibroblasts produce a factor that increases the survival of CFUs, which may be involved in the role of marrow stroma in the control of haemopoiesis.
Subject(s)
Hematopoietic Stem Cells/cytology , Animals , Bone Marrow/growth & development , Cell Survival , Cells, Cultured , Culture Media , Fibroblasts , Male , Mice , Mice, Inbred CBA , Time FactorsABSTRACT
Evidence is presented that in human granulocytes the immediate precursor pool of phenylalanine for protein synthesis in vitro is intracellular significant compartmentation.
